Understanding Disparities in the Pediatric ICU: A Scoping Review.

BACKGROUND AND OBJECTIVES: Health disparities are pervasive in pediatrics. We aimed to describe disparities among patients who are likely to be cared for in the PICU and delineate how sociodemographic data are collected and categorized. METHODS: Using MEDLINE as a data source, we identified studies which included an objective to assess sociodemographic disparities among PICU patients in the United States. We created a review rubric, which included methods of sociodemographic data collection and analysis, outcome and exposure variables assessed, and study findings. Two authors reviewed every study. We used the National Institute on Minority Health and Health Disparities Research Framework to organize outcome and exposure variables. RESULTS: The 136 studies included used variable methods of sociodemographic data collection and analysis. A total of 30 of 124 studies (24%) assessing racial disparities used self- or parent-identified race. More than half of the studies (52%) dichotomized race as white and "nonwhite" or "other" in some analyses. Socioeconomic status (SES) indicators also varied; only insurance status was used in a majority of studies (72%) evaluating SES. Consistent, although not uniform, disadvantages existed for racial minority populations and patients with indicators of lower SES. The authors of only 1 study evaluated an intervention intended to mitigate health disparities. Requiring a stated objective to evaluate disparities aimed to increase the methodologic rigor of included studies but excluded some available literature. CONCLUSIONS: Variable, flawed methodologies diminish our understanding of disparities in the PICU. Meaningfully understanding and addressing health inequity requires refining how we collect, analyze, and interpret relevant data.

Salinity and total suspended solids control mercury speciation in a tidal river: Comparisons with a photochemical mercury model.

Daytime volatilization of gaseous elemental mercury (Hg(0)aq) is a significant mechanism for mercury removal from aquatic systems and potentially limits the production and bioaccumulation of methylmercury. Changes in incoming solar radiation (in the ultraviolet range), dissolved organic matter, salinity, and total suspended particles were investigated concurrently with several mercury species (Hg(0)aq, dissolved total mercury (THg), easily reducible mercury (ERM), and mercury associated with total suspended solids (THgTSS)) during daylight hours near the mouth of a hypertidal river. There were no predictable temporal changes observed for Hg(0)aq in unfiltered surface water. Hg(0)aq ranged from 0 to 12 pg L-1, THg ranged from 0 to 492 pg L-1, ERM ranged from 13 to 381 pg L-1, and THgTSS ranged from <1.58 ng g-1 to 261.32 ng g-1. The range of Hg(0)aq predicted by the empirical model was similar to measured ERM concentrations, but it was shown that ERM did not significantly predict in-situ photoreducible Hg(II) (Hg(II)RED). Production of Hg(0)aq appears to largely be suppressed by suspended solids, which limits ultraviolet radiation transmission through surface water. Comparison of these results to an empirical model developed for this site to predict Hg(0)aq indicates that significantly more mercury is available for photoreduction near the mouth of the tidal river, and that Hg(II) will likely photoreduce quickly when TSS levels decrease with ocean mixing.

Mercury photoreduction and photooxidation kinetics in estuarine water: Effects of salinity and dissolved organic matter.

Net photoreduction of divalent mercury (Hg(II)) and volatilization of photoreduction products (i.e., elemental mercury (Hg(0))/dissolved gaseous mercury (DGM)) is a mechanism by which mercury burdens in ecosystems are lessened. The effects of salinity on mercury photoreactions were investigated while controlling the concentration of DOM (>1 kDa) using natural surface water from the tidal Jijuktu'kwejk (Cornwallis River) and processed with a tangential ultrafiltration-dilution technique. Pseudo first-order rate constants in estuarine water salinity dilutions ranged between 0.22 h-1 and 0.73 h-1. The amount of mercury available for photoreduction (Hg(II)RED) ranged between 67.2 and 265.9 pg. Pseudo first-order rate constants decreased with increasing salinity treatments (0-13.5 g L-1), with minimal change in rate constants occurring in higher salinity treatments (e.g. 20.3 or 26.8 g L-1), while Hg(II)RED increased with salinity. In lower salinity treatments, DOM was more photoactive. Taken together, results suggest changes in the mercury photoreduction mechanism from DOM-bound electron transfer to photochemically produced secondary reduction products with increasing salinity. Experiments examining photooxidation showed decreases in Hg (0) with longer exposure time, suggesting transformation of Hg(II)RED into a non-reducible form. This research highlights the importance of salinity and DOM interactions in estuarine surface water and their effects on mercury photochemistry.

Methylmercury in caddisflies and mayflies: Influences of water and sediment chemistry.

Quantifying methylmercury (MeHg) concentrations and uptake at the base of the food web is useful for assessing mercury exposure risk to higher trophic level organisms. Higher MeHg concentrations near the base of the food web may result in more MeHg exposure and accumulation in higher trophic organisms. Here, we analyze MeHg in caddisflies, mayflies, lake water, and sediment collected from two temperate lakes and one brook in Kejimkujik National Park, Nova Scotia, Canada. Overall, caddisfly larvae MeHg (15.38-276.96 ng/g; n = 29) was not significantly correlated with water chemistry. Whereas mayfly naiads MeHg (14.28-166.82 ng/g; n = 31) was positively correlated with water MeHg (rs = 0.43), negatively correlated with pH (rs = -0.49), and positively correlated with dissolved organic carbon (DOC; rs = 0.48). Of the mercury in insect tissues, the %MeHg ranged from 56 to 75 % in caddisfly larvae and 38-47 % in mayfly naiads. MeHg bioaccumulation factors (BAF) varied greatly (water to tissue BAFs = 0.145 × 106-1.054 × 106; sediment to tissue BAFs = 0.017 × 106-0.541 × 106). This study highlights the importance of quantifying variations in MeHg bioaccumulation and BAFs of common aquatic insect bioindicators at the base of complex food webs.

Paved With Good Intentions: Hospital Visitation Restrictions in the Age of Coronavirus Disease 2019.

Hospital visitation restrictions have been widely implemented during the coronavirus disease 2019 pandemic as a means of decreasing the transmission of coronavirus. While decreasing transmission is an important goal, it is not the only goal that quality healthcare must aim to achieve. Severely restricted visitation policies undermine our ability to provide humane, family-centered care, particularly during critical illness and at the end of life. The enforcement of these policies consequently increases the risk of moral distress and injury for providers. Using our experience in a PICU, we survey the shortcomings of current visitation restrictions. We argue that hospital visitation restrictions can be implemented in ways that are nonmaleficent, but this requires unwavering acknowledgment of the value of social and familial support during illness and death. We advocate that visitation restriction policies be implemented by independent, medically knowledgeable decision-making bodies, with the informed participation of patients and their families.